In all piping systems, there is utilized generally a number of "fittings" which are used to configure the pipline or piping system to a desired chemical plant, or to the terrain across which it is flowing, or otherwise to change the pipeline configuration and position. Such fittings are known in the art as elbows, tees, crosses, valves, flanges, and the like. A fitting is generally referred to hereinafter as any portion of a pipeline which is connectable to a normal pipe joint, the fitting being a portion of the pipeline which can create turbulence and which can be a spot for potential leaks.
Leaks in fittings are generally created by corrosion or mechanical deterioration. This is often seen in the oil and gas industry where natural gas and/or oil flowing from a well is often combined with sand and the flowing produces a sandblasting effect. This sandblasting effect especially eats away at elbows, tees, choke jackets, and valves when the pipeline makes a turn. It is known in the art that turbulence is increased at such turning points in the pipeline.
In the production of natural gas, a well is normally drilled with a length of pipe known as a "drill string". The drill pipe is individually made up of sections which can be, for example, thirty feet (30'). The drill pipe is enclosed normally in a casing which is also welded or jointed. Casing is then cemented into place from the bottom up. At the head of the casing, the crew installs a master valve that may be closed quickly and surely to shut off the flow of gas. Above this valve is placed a "Christmas tree". A Christmas tree is merely an assembly of pipes and valves that allows the gas to flow into gathering lines. These gather the output of several wells and carry the fuel to the cross-country pipelines for remote transmission of the gas. It is to this general field that the present invention is directed.
Several devices have been patented which have attempted to provide a method for the detection of leaks in flow lines and in fittings which have been corroded by chemical or weather attack, or mechanically deteriorated as in the case with sand/gas combinations. The following table provides a list of some prior art devices which have been patented.
______________________________________ PRIOR ART PATENTS U.S. Pat. No. Inventor(s) Issue Date ______________________________________ 2,280,140 J. H. Wilson 04/21/42 2,607,225 P. H. Biscoe 01/23/48 2,765,801 F. E. Selim 10/09/56 2,937,520 A. Bell 05/24/60 3,339,415 W. Wild 09/05/67 3,339,728 A. R. Taylor 09/03/68 ______________________________________